Cartridge fuse



Feb. 19, 1929. 1,702,355

C. T. M DONALD ET AL CARTRIDGE FUSE Filed Fe 1925 2 Sheets-Sheet l Feb. 19,1929.

. c. T. MCDONALD ET AL CARTRIDGE FUSE Filed Feb. 9, 1925 2 Sheets-Sheet 2 dmma Lac/ QM Patented Feb. 19, 1929.

UNITED STATES PATENT OFFICE.

CLARENCE T. MCDONALD Aim HERBERT R. C OK, or CHICAGO, ILLINbI S, nss GnORs 'ro CHICAGO JEFFERSON FUSE & ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A

CORPORATION OF ILLINOIS.

CARTRIDGE FUSE.

Application filed February 9, 1925. Serial No. 7,759.

This invention relates to cartridge fuses the so-called knife blade type, and one of the objects of the invention to produce a iu of this type in which a majority of the '0 individual elements which it is necessary to remove from the casing in the operation of refilling the fuse are secured together as a unit, so that tire number ot separate pieces be handle while refilling the fuse is re o ced to a minimum. To this end the invenfurther object oi. the invention is to proe novel means i'or ClOSlDO the casin and c o 1 a the terminal blade unit in place "lit r secu' n erein in such a manner that the said unit be quickly removed from the casing and ed and secured therein when rehlling In carrying out this ob ect we have i-rovided a construction and relation- ,.ad and head by which the lixcu position in the casing. objects and advantages of the in- ;jion \l'i'll be understood from the follow- .ition, taken in connection r onipanying drawings, in which a lo itudinal central secti nal 'l'use embr'idying the J our 'nvention, the terminal biade i 1 shown in elevation. 2 is longitudinal section taken in a ph at right angles to Fig. 1. i Fig. 3 is a sectional detail view showing one l closing washers.

i is an end elevation of the casing head cooperates with the washer seen in seen in Fig.

Fig. 8 is an elevation of one form of terminal biade unit removed from the casing.

9 is a perspective view of one of the clips of the bridge section.

Figs. 10 and 11 are views similar to Fig. 8 but showing modified forms of terminal blade units carrying two and four fusible ele ments respectively.

i. and 13 are perspective views 0: the end clips of the bridge sections used in the forms shown in Fi s. l0 and 11 respectively.

Fig. 14 is a section taken in the plane of line l4-1-fl of Fig. 8.

Fig. 15 is a detail View of a fusible element.

While we have shown in the drawings and will herein describe in detail the preferred embodiments of our invention, we desire to have it understood that this disclosure is given for the purpose of reoresentingsome or the spe liiC of carrying out our invention and is not intended as a limitation thereof to the constructions disclosed. We aim to cover in the appended claims all modifications and alternative constructions falling within the scope of the invention as limited by the state of the prior art.

In the preferred embodiment of the invention herein shown the fuse comprises a tubular casing composed in the present instance of an insulating tube having two metallic heads 21. attached opposite ends thereoi in any suitable v. The head has at one end a plurality of abutments or webs 23, in this instance tour, extending radially inward, the adjacent pairs of said webs forming between them i )CliQl'F; or recesses 24 which receive ho formed on the inner face of a disk which constitutes a closure for the end of the using. This disk has a diametrical slot through which one of the terminal blades extends. The cooperating recesses and bosses .,3 prewnt rciative rotation of the head 21 the one hand and the disk 26 and its teral blade on the other, for a purpose to be presently explained. A clamping member, which in this instance is in the form of an annular cap 27, surrounds the terminal blade and has threaded engagement with the head 2i to secure the disk 26 in place.

The other head 22 has a web or end wallv For this purpose the disk has a laterally ofi set portion 31 which is defined by an ar cuate edge 31 and a chord-like edge 31, the latter being irregularly shaped to conform to the same part on the terminal blade which seats in the recess 29 in the end wall of the head 2 The terminal blade unit as whole, in the preferred forms herein shown, comprises two blades 32 each carrying a ledge or continuous shoulder 33; one or more fusible elements 34: connecting said blades; a bridge section composed of two metallic clips 36 embracing said blades and JOlIlGtl by an insulat-ing bar 37 and the disk 26 carried by and fixed to one of said blades. The inner portions of the blades are narrower than the outer portions forming shoulders 38 which abut against the outer faces of the webs and 280i the heads 21, The ledges 33 are, in thisinstance, composed of small oblong plates having rounded ends and having central slots which may be slipped over the narrower portions of the blades. Said ledges lie closely along the shoulders 38 on the blades and are secured rigidly to the blades in any suitable way as, for example, by upsetting the adjacent edge portions of the blades as seen at 39. These ledges are shorter in length than the width of the wider portions of the blades to leave portions of the shoulders 38 on the blade exposed, but the ledges are wider than the thickness of the blades for a purpose to be later explained.

The disk 26 is preferably lied perinanently to its blades although such perma nent relation is not essential. In the present instance the disk abuts against the adja cent ledge 33 and is so locked by upsetting the edges of the blade along the outerface of the disk as indicated at 26.

Each of the clips 36 of the bridge section comprises two perpendicular portions, one of which has an aperture or slot 27 to be slipped over the narrower portion of the blade and the other of which extends parallel to the blade and is attached to the insulating spacer bar 37 of the bridge. T he fusible element or elements are secured to the blades in the present instance by bolts 40 passing through apertures in the element and the blades and having nuts 41 whereby the element may be tightly clamped. In the particular construction shown in Figs. 1, 2 and 8 wherein a single fusible element is mosses used, the bolt passes first through a washer 42, then through the apertures in the fusible element and the blade and then through an aperture in a portion of the clip of the bric ge section, said clip portion inthis form extending directly alongside the face of the blade and being clamped thereto by the bolt and the nut. Said clip portion is offset at 123 immediately adjacent to the periphery of the nut and thereby holds the nut rom turning so that the bolt and nut may be tightened by a single tool applied to the bolt head.

In the ft) in of bridge unit seen in 10 wherein two fusible elements 39; are used, the sr d elements are pr rably located at opposite sides of the blade ends and enibraced by a pair of washers against which the heads of the bolts 4.0 and the nuts ll bind.

In this arrangement it is desirable that the bridge section be spaced farther away from the plane of the blades and therefore the portions of the clips 36 which extend parallel to the blades are spaced from the blades. In these clip portions we preferably provide aitei lures eldof hexagonal or other non-circ lar snape to receive and conform to the peripheral shape of the nuts ell whereby the nuts will be held against turning so as to permitof using a single tool on the bolt heads for tightening.

In the form of blade unit seen in ll wherein four fusible elements are red, two of said elements are located on each side of the plane of the blades and the two elements at one side are spaced apart by me tallic collars 45 through which the bolts 4&0 extend. In this form the portionsof the clips 36 which are parallel with the blades are necessarily spaced farther from the blades to accommodate the fuse elements and to receive the nuts 41.

The clips shown in Figs. 10 to 13 are not clamped by the bolts and nuts 40, ll, and therefore it is preferable t provide for stabilizing the clips and prevenli rocking thereof on the blades. he n".- herein shown for that purpose conn lugs 46 bent up from the clips along the edge of the blade-receiving slots E2" therein, said lugs extending along and engaging thefaces of the blades. If desired apertures e8 may be provided in the clips and blades to receive screws ll so as to provide a more rigid fastoning.

lVhen it is necessary to renew or refill the fuse the end caps 27 are removed from the heads 21, 22, and he dist: 30 is slipped off the end of its blade. whereupon the entire blade unit may be withdrawn from the casing through the left hand end thereof as viewed in the drawings, it being necessary in-be ginning this removal to move the right hand blade transversely to the axis of the fuse so as to disengage the shoulders 38 from the abutment portions 28 of the end wall 28 tai liitl ders, a metallic head having; an end Well closing' a portion of the opening through the head but leaving an aperture having an eccentric portion through which said blade may be passed through the head and a narrow portion central of the head adapted to receive said abutment and having portions opposite ends of the narrow portion of said aperture against which said shoulders abut to prevent movement of saidblade inwardly in the heed and means including a disk which closes the opening in the head cooperating with said abntnient to prevent outward inovemeut of said blade and also enacting with said head to hold said blade ag'iinst movement transverse to the axis of the head or rotary inoven'ient about such axi;

3. A terminal blade unit for cacti-i fuses comprising two blades, a fusible ele ment oining said blades and a brid section joining said blades and comprising inetallic clips attached to the blades and joined by an '-s11lating nn-iniber said clips being readily removable from strid blades to permit substitution of a new bridge section.

l. A terminal blade unit for renewable cartridge fuses comprising, in combination two blades, a fusible element joining said blades and a bridge section said blades, and comprising two metallic end clips joined by an insulating men'iber, said end clips comprising portions lying parallel to the blades and perpentucnler portions vfiich are sperturcd to embrace adjacent ends of the blades v-Jhereby the clips are readily removable from the blades.

A terminal blade for renewable cartridge coniprisii con'ibination, two blades, 2i bridge section joii no; said blades and comprising two metallic clips joined by an insulating inei'nber each clip comprising; portion extending perpendicular to its blade and apes aired to removablv embrace th hlzid r and another portion extending; parallel to its blaoe and havii'ig nut-receiving: apcrture therein, a fusible element and means for fastening the ends of said fusible element to said blades comprising two bolts passing through said element and said blades and nuts on said bolts seated 111 said nut-receWingapertures 111 said clips.

pectire blades said bridge J'XA'l to cooperate with sand rci'cnt rotation of 21, por- 7. cartridne two b l s and for renewable 'ipris in ceinbnuition,

A M 7 n lades, section join a said insulating:

a main allel to the blades and ions lnw 7 parts perides and ilp jl'llllil to peumcular to the o embrace the latter.

8. ill teunina blade unit for renewable ce *idgsje conn ising' in combination, two blades. zr-n insulat 3; briC section oinll ising a main insu- I inn; said dflQS and cornpr lating portion extending, parallel to the blades and two metallic end members having portions perpendicular to the blades and apertured to en'ibrace the la tter fusible element and devices for securing; said element to said blades, said bridge section cooperatinn with SiiKi ices to facilitate the manipulation of the zit-tier.

9. A terminal blade unit for renewable 'isi w in coinbinatioin cartridge fuses con i two blades, an insulating bridge 1oz joining said blades s Id brid e section. coinprisine; .ietallic end portions having; apertnres therein through which the adjacent ends of said 1' des orejeet.

10. A i Mal blade uniteartridggje fuses comprising. i two blame i {in insi l ting brido'e section joining said blades comp:'ising metallic \nds having apertur therein through which the adjacent ends o said blades project, a fusible element and rerxomdde devices for teningg; said clcn'iont to s-cid blades v said blades be t withdreweblo from the apertures in said bridge section when said fastening;- de

ior renewable n combination,

aflirred our signatures.

lliiill l hiloDONiiLl).

H.151 ll lli'll R. COOK. 

